Surprise, I want to make ponies.
Is there a means by which one can have separate 'stock' models, with rigging and such? It'd probably be one of the most flexible things to add, if it's not already in. You could have animals, fictional stuff, even things like modular housing could be designed by snapping together the ingredients. Sub categories and "bolts" (tag points, or tag surfaces) could be used if they're not in, that way one can keep things arranged, and have the ability to extend the model by repeatedly hooking up things from joint to joint (more effective for houses for rooms/layers or fictional creatures with multiple segments). With joints and some collision detection, one could have quite a bit of fun with it, by say stuff like off-center headgear, people with multiple arms, a 6-legged alien with a hominid thorax.